<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        // node 环境和 浏览器环境不太一样
        async function async1() {
            console.log('async1 start');
            await async2();
            console.log('async1 end');
        }
        async function async2() {
            console.log('async2');
        }
        console.log('script start');  //1
        setTimeout(function () {
            console.log('setTimeout');
        }, 0)
        async1();
        new Promise(function (resolve) {
            console.log('promise1');
            resolve();
        }).then(function () {
            console.log('promise2');
        });
        console.log('script end');

        // 【注意】async 函数与await 函数内的会立即执行 await 后面的会进入 微任务等待

        // script start
        // async1 start
        // async2
        // promise1
        // script end
        // async1 end
        // promise2
        // setTimeout


        // 2.await
        function wait() {
            return new Promise(resolve =>
                setTimeout(resolve, 10 * 1000)
            )
        }
        async function main() {
            console.time();
            const x = wait();
            const y = wait();
            const z = wait();
            await x;
            await y;
            await z;
            console.timeEnd();
        }
        main();


    </script>
</body>

</html>